1. Field of the Invention
The present invention relates to an ophthalmometric apparatus and, more specifically, to an ophthalmometric apparatus for examining and observing a desired part of the examinee's eye through the pupil.
2. Description of the Related Art
An ophthalmometric apparatus aligning method using the bright spot of corneal reflection is used widely for aligning an ophthalmometric apparatus with the examinee's eye in a predetermined positional relationship.
This ophthalmometric apparatus aligning method adjusts the vertical and the horizontal position of an ophthalmometric apparatus relative to the examinee's eye by locating the bright spot in a predetermined positional relation with an image of a reticle on the screen of a TV monitor, and adjusts the axial position of the ophthalmometric apparatus relative to the examinee's eye so that the bright spot is reduced to a minimum size by axially moving the ophthalmometric apparatus; that is, the axial position of the ophthalmometric apparatus is adjusted so that the ophthalmometric apparatus is focused on the bright spot.
Although such a known ophthalmometric apparatus aligning method is effective in setting an ophthalmometric apparatus in a predetermined positional relation to a reference point for alignment in the examinee's eye, the bright spot is blurred when the ophthalmometric apparatus is shifted axially away from the examinee's eye from the position in the predetermined positional relation to the reference point for alignment, for example, when measuring the opacity of the crystalline lens, and the blur of the bright spot is enhanced as the ophthalmometric apparatus is shifted away from the examinee's eye from the position corresponding to the reference point for alignment. Therefore, when measuring a point other than the reference point for alignment, it is difficult to observe the measured point on the screen of the TV monitor because the bright spot is blurred.